<!DOCTYPE <!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>布局div test</title>
</head>

<body>

    <div id="container" style="width:400px">

        <div id="header" style="background-color: aqua;">
            <h1 style="margin-bottom: 0;text-align:center;">ATU 专业行培训计划</h1>
        </div>

        <div id="content" style="background-color:aliceblue;height:100px;width:300px;float:left;text-align:center;">设计一个网页</div>

        <div id="menu" style="background-color:aquamarine;height: 100px;width: 100px;float: left;text-align:right;"><b>HTML<br>CSS<br>bootstrap4<br>JavaScript</b></div>

        <div id="footer" style="background-color:blanchedalmond;clear:both;text-align:center">版权 ATU 专业性培训</div>

    </div>

</body>

</html>